Pool cleaner disc

Abstract: A disc for use with an automatic swimming pool cleaner which operates on a substantial intermittent reduction in water flow through the swimming pool cleaner, the disc being made of flexible material and having grooves formed symmetrically across and into the under surface of the disc.

Description: This invention relates to discs which are used on certain kinds of swimming pool cleaners primarily to hold the pool cleaner against the surface which is to be cleaned. These discs are made of flexible material so that they can, under operating conditions, follow the contours of the floor and walls of a swimming pool. Particularly the flexibility enables the swimming pool cleaner to traverse the corner formed between vertical and horizontal surfaces. Usually, a compromise must be reached in obtaining the desired flexibility while still maintaining the disc properly functional under the suction induced by water flow through the cleaner. It is the object of this invention to provide a disc which not only improves operation of the pool cleaner with which it is used but will also facilitate packing for transport and storage. US-A-4 193 156, on which the preamble of claim 1 is based, discloses a disc for a suction operated pool cleaner, the perimetral region of which is corrugated or wrinkled and has a number of concertina-like folds. According to the present invention, there is provided a disc for a suction operated swimming pool cleaner, made of flexible material and having a central aperture to engage around the head of the suction operated pool cleaner, wherein grooves are formed symmetrically into and across the surface of the disc which is arranged to engage a pool surface to be cleaned, characterised in that the grooves extend from the periphery of the disc to said central aperture. Further features of this invention provide for the grooves to be at least predominantly radially located or for a pair of grooves spaced apart on each side of a diametrical centre line to be provided or for a combination of both patterns of grooves to be provided. The invention also provides for the grooves to be about 5 mms wide and to extend to a depth about three quarters through the thickness of the disc material. Preferred examples of this invention are described below with reference to the accompanying drawings in which Figs 1 to 3 illustrate different patterns of grooves Figs 4 and 5 illustrate two ways of folding the discs and Fig 6 is a detail. The flexible disc (1) with which this invention is concerned may be used with different kinds of suction operated pool cleaner which consist essentially of a head having a passage therethrough. The inlet end of the passage opens in use adjacent to the surface being cleaned and the disc fits around the head adjacent the inlet. It is rotatable relative to the head. The outlet from the head is connected to the suction hose for the filter plant for the swimming pool. The head includes a mechanism which intermittently causes a substantial reduction or interruption of the flow through the head. This in turn results in forces being generated in the pool cleaner which causes the cleaner to move in stepwise manner over the surface to be cleaned. The disc (1) stabilises the cleaner on the surface being cleaned and its movement over the surface assist in dislodging dirt and debris from the surface to facilitate entrainment of this material into the filter plant. The disc is particularly suitable with the swimming pool cleaner sold internationally under the trade marks "Baracuda" and is disclosed in US Patent Nos. 4,133,068 4,642,833 and "Kreepy Krauly" U S Patent No. 4,023,227. The disc (1) of this invention has grooves provided in the underside, that is the side in contact with the surface to be cleaned. These grooves, as indicated in Fig 6, where the thickness of material (2) is about 3 mm, will be about 2,5 mm deep and about 5 or 6 mm wide. In Fig 1 there are a pair of grooves (3) one on each opposite side and parallel to a diametrical centre line. This enables the disc to be folded into the shape shown in Fig 4. In Fig 2 the grooves (4) extend radially from the centre hole and this configuration of grooves enables the disc to be folded into the fan shape indicated in Fig 5. The disc can be retained in this fan shape for storage and transport with simple clips indicated at (5). Fig 3 shows a combination of the grooves (3) and (4) in Figs 1 and 2. The usual array of symmetrically arrangement of small holes (6) is provided to reduce the force with which the disc adheres to the surface being cleaned when the cleaner is in use. It will be appreciated that the greater the number of grooves the more flexible the disc becomes in use. This has a marked effect on the kind of material which may be used and on the method of manufacture of the discs. For example a polyurethane disc of 82A hardness with grooves will give a better performance than the usually required softer material of 78A. This latter material often gives rise in difficulty in arriving at a desired flexibility and instability of the pool cleaner during use. The possibility exists that the discs can in the future be moulded in the folded shapes illustrated. The advantages of this are significant. The current projected area requires a large and robust die set, inevitable a single cavity set, with individual pins for individual holes (6) and the associated flashing problems. By moulding in one of the folded conditions, the projected areas can be reduced by half or quarter, or even less if the moulding is effected edge on. Also holes (6) could be made using retractable through pins, in one possibility each pin producing up to 6 holes. Also multi-cavity dies or singles on smaller machines becomes a possibility with the associated cost savings. The discs (1) can be folded for packaging and storage with consequent savings in space and packaging materials. Experience has shown that when the discs (1) are folded into the shapes indicated in Figs 4 and 5 they will soon return to the flat operative position when used. This return will of course be more quickly achieved if the discs are laid flat in the sunshine before being put into a pool. The provision of the grooves (3) thus enables a better performance to be obtained at lower overall cost.

Claims: A disc (1) for a suction operated swimming pool cleaner, made of flexible material and having a central aperture to engage around the head of the suction operated pool cleaner, wherein grooves (3,4) are formed symmetrically into and across the surface of the disc which is arranged to engage a pool surface to be cleaned, characterised in that the grooves (3,4) extend from the periphery of the disc to said central aperture. A disc as claimed in claim 1, characterised in that the grooves (4) are symmetrically located and extend predominantly radially across the under surface of the disc (1). A disc as claimed in claim 1, wherein a pair of parallel grooves (3) are provided symmetrically one on each side of a diametrical line across the disc (1). A disc as claimed in claim 1, wherein a combination of grooves (3,4) defined in claims 2 and 3 are provided. A disc as claimed in claim 1, wherein the disc (1) is made of polyurethane of 82A hardness and the grooves extend about three-quarters through the thickness of the disc material. A disc as claimed in claim 5, wherein the grooves (3,4) are 5 mm wide and 2.5 mm deep.

Inventors: ATKINS DAVID SEAGRAVE, ATKINS, DAVID SEAGRAVE
Applicants: ZARINA HOLDINGS CV
Application year: 1994
Main classification: E04H4
IPC codes: E04H4